Log Message:
chat/py-matrix-common: Update to 1.3.0

upstream NEWS content:

    Drop support for Python 3.6, which went end-of-life December 2021 by \ 
@anoadragon453 in #28
    Configure setuptools to automatically discover new modules under
    src/matrix_common by @anoadragon453 in #27
    Add a MXCUri class for representing Matrix media uri's by @anoadragon453 in #29